When you're looking into the world of "clean" amp tones, the hallmarks are basically British or American. Essentially, EL84 tubes or 6L6 tubes. Most modeling amps will distinguish between these two "clean" tones.
The America style clean trademarked by Fender in their 60's and 70's lines of tube amps is a crystal clear true-to-tone clean amp signal. Amps like the Princeton, Twin Reverb, Vibrolux, Tone Master, and the like all featured the 6L6 power tubes akin to this type of tone. High head room and low breakup is the character of this tone. Low breakup, meaning that the amp is difficult to overdrive. Even at high volumes. These amps graced almost every recording of these era's of music. If it was crystal clean, it was probably a Fender blackface amp. The later "silverface" models were updates on the older models and added a little more bite... On popular modeling amps, this is usually denoted by either American, US, or Cali.
The British style of clean tone comes from the Vox AC30 and eventual AC15 of the same era. These amps feature the EL84 tubes in the power section. These amps were made famous by none other than The Beatles.They had a chime to them that is unmistakable by most veteran recording artists and engineers. These amps have a higher propensity to break up at lower volumes and grabbed the ears of players who wanted a more versatile amp. Brian May famously used these as well. These aren't to be confused with Marshall amps... Which were designed to breakup and give that famous Marshall tone that fueled the harder rock and metal scenes of the 80's. Most modeling amps distinguish this clean tone as AC, UK, or Brit.
So, yes there are different flavors of clean tones. Some amps don't get into the modeling to a point that they make this distinction. Some have amp models, cab models, and even gain models for different levels of volume for these amps. That all depends on the modeling amp you're looking. Be advised that modeling amps are jacks of all trades and masters of none. They do things only to a loose point of accuracy. There's no real substitute for a real tube amp in either of these veins. I've played and owned both and can say that you'd probably be better off buying one and putting some pedals into it than getting a modeling amp. That's just my advice though.
